Process for coating metal articles with other minerals.



WILLIAM GEORGE CLARK, OF LONDON, ENGLAND.

PROCESS FOR COATING METAL ARTICLES WITH OTHER MINERALS.

No Drawing.

To all whom it may concern:

Be it known that I, WILLIAM GEORGE CLARK, subject of the King of GreatBritain, residing at No. 36 New Broad street, London, England, haveinvented a new and use ful Process for Coating Metal Articles with otherMinerals, of which the following is a specification.

This invention relates to improvements in the process whereby copper, oran alloy thereof, is caused to form a coating to the surface of iron andsteel plates or other articles composed of such a metal which will bereferred to hereafter as iron this metal constituting the aramountingredient.

The purpose of this invention is to render the copper or alloy coatingabsolutely continuous and indivisible from the iron under suchmechanical treatment as may tend to separate the layer in an intactcondition.

The advantages to be derived from the invention are the perfectprotection of the iron from corrosion by the absolute continuity and thecomplete adherence of the coating and the provision of means whereby twoadjacent plates of iron may be united throughout their entire area ofcontact without requiring them to be subjected to a temperature inexcess of that required to melt the copper or the alloy whichconstitutes the coatlng.

Iron has been previously coated with copper by immersion in a solutionof copper salt, with and without electrolytic action, after the chemicalcleansing of the surface of the iron, and attempts have been made tomore thoroughly secure the deposited film of copper to the iron byheating the coated article to the temperature of melting copper. Thisprocess has been only partially successful because the heating has takenplace under circumstances which would permit of some of the copperbecoming oxidized.

According to the present invention the coating of copper or alloythereof is, during the heating operation, rotected from oxidation bybeing covered by a molten nonoxidizing substance composed for example ofone or more of the fiuxcs borax, boracic acid and carbonate of soda andpreferably of a mixture of the three, this substance be ing capable ofbeing maintained at the temperature at which copper will melt withoutserious loss by volatilization or other deterioration and having at thattemperature Specification of Letters Patent.

Application filed October 27, 1911.

Patented May 6. 1 91 3.

Serial No. 657,076.

such a viscosity as to enable it to adhere to the heated surface. pointof the metal of the coating, is transmitted thereto through the mediumof the molten flux by which it is covered whereby every portion of thesurface is equally protected and heated. ()n removal of the coated irona film of the flux will adhere thereto and provide a subsequentprotection until removed by abrasion, rolling, washing or otherwise.

By the present invention the adherence of copper to thin plates or otherarticles of ironcan be rendered as perfect as the adherence of tin orzinc to such iron articles by the process of immersion of the ironarticles into the molten metal. On account of the relatively much highertemperature of fusion of copper the corresponding operation of immersionof thin iron into molten copper so deteriorates or destroys the ironfoundation as to render the process impracticable. By limitin thequantity of molten copper which is welded on to thin iron articles bythe process of the present invention the evil effects which would be dueto immersionin molten copper are avoided. In the case of thin ironplates or other iron articles which are not plates, the articles arecaused to receive the coating of copper or alloy thereof by immersion ina solution of a salt of the metal and the coating is subsequently weldedon to the iron foundation by immersion in the previously describedmolten flux which is subjected to a temperature approximately that atwhich copper or the alloy which constitutes the coating will melt. Onremoval from the bath of flux, the adherent film will protect the surface from oxidation until cooled and thereafter if not mechanicallyremoved. If it is desired to weld to a thick plate of iron a coating ofcopper or other alloy on one face thereof, the plate with the coatedsurface upward may be covered with the flux and the temperature raisedto the meltin r point of the coating metal, and an additiona quantity ofthe coating metal may be added in the molten or solid condition toproduce a. thicker coating. When it is desired to unite two iron plateseach of which has been coated with copper or an alloy thereof. as abovedescribed, the plates are superposed with the coated surfaces facingeach other and the films of congealed flux interposed to which Heat, upto the melting additional flux may be added. After rais- 1 ing thetemperature of the compound plate to that of the melting point of thecoating of copper or alloy thereof, the compound plate is subjected topressure to squeeze out the interposed liquid flux as for example bypassing the two plates between rollers pressed forcibly together and thetwo plates will be perfectly unit-ed throughout their entire area ofmutual contact.

I claim:

1. A process for coating iron articles with another metal and adherentlysecuring said coating thereto, consisting in immersing the iron articlein a solution of a salt of said other metal and heating said therebycoated iron article in molten non-oxidizing flux to the fusiontemperature of said other metal.

2. A process for coating iron articles with copper and adherentlysecuring said coating thereto, consisting in immersing the iron articlein a solution of a copper salt and heating said thereby coated ironarticle inmolten non-oxidizing flux to the fusion temperature of copper.

' In testimony whereof I have signed my name to this specification inthe presence of two subscribing Witnesses.

WILLIAM GEORGE CLARK.

Witnesses:

FREDERICK WILLIAM LANE, HERBERT D. JAMESON.

